Terra I supplies Earth with Zenbar crystals, which is used to supply 72% of the power to Earth. Ordinarily, a computer controls the defense systems but it looks to have been sabotaged. Space pirates are in the area and the robot interceptors are working against us. Your orders are to fly your F-117 Starwarrior to Terra I, destroying anything that tries to harm you.
You can move your ship up, down, left or right. You begin with a top-down view if the F-117, facing towards the bottom of the screen. Meteors and later space pirates come from the bottom moving up and you must shoot them. After you get through these, you switch to a side view of the ship and face left or right. Robot interceptors will come from the sides and must be destroyed then fish force fields (yes, fish force fields) will come from the top, moving down and you must shoot the fish-shaped devices to destroy them. They are Terra I's last defensive line so when you get through them, you win.
In the two player games, player one controls the F-117's left and right movement and player two controls the up and down movement therefore players must work together. Firing alternates between both players in two second intervals.
Description courtesy of MobyGames
via a CC license